1. Field of the Invention
The present invention relates to drill guides and other medical instruments that are attached to medical implants such as intramedullary nails which assist in the performance of surgical steps such as targeting and guiding the installation of bone screws from outside the body. More particularly, the invention is directed to a tool that facilitates the detachment of drill guides and the like from medical implants and minimizes the time to perform the detachment step and the size of the incision through body tissue in the vicinity of the implant.
2. Description of the Prior Art
During a procedure to insert an intramedullary nail, a drill guide is connected to the intramedullary nail with a connecting bolt. The connecting bolt is threaded into the proximal end of the intramedullary nail aligned generally with the longitudinal axis of the intramedullary nail. During insertion of the intramedullary nail into the patient, a mallet is used to strike an insertion driver which communicates the impact through the drill guide to the intramedullary nail. After insertion of the intramedullary nail, the drill guide provides alignment for drilling transverse bores through the bone to accommodate transverse screws to lock the intramedullary nail to the bone. In addition, other orthopedic devices that require precise alignment or sturdy connection to the intramedullary nail, such as drills, modular drill guides, reaming devices, guide tubes, guide pins, fasteners, or removal drivers, can be attached to the drill guide.
The connection of the drill guide to the intramedullary nail is an important part of the femoral shaft fracture procedure. The connecting bolt is often obscured by soft tissue and cannot be seen by the surgeon. Getting a tool to the connecting bolt can be difficult, may require several minutes, and often results in soft tissue damage. In addition, a large incision is often required to accommodate the required tool. An example of such a drill guide showing a conventional attachment is disclosed in U.S. Pat. No. 4,911,153.
One prior art device, the Synthes drill guide, allows remote actuation of the connecting bolt. However, the Synthes device achieves remote actuation through a long, bent neck for guiding a universal-jointed driving tool to the bolt. The neck is permanently attached and continuously interferes with soft tissue during the medical procedure. In addition, the bolt used with the Synthes device is not cannulated. Cannulation of the bolt is desirable to allow the surgeon access to the interior of an implant.
It is an object of the present invention to provide an attachment tool for an implant drill guide that can be remotely actuated with minimal soft tissue damage. It is a further object of the present invention to provide an attachment tool that is capable of using cannulated fasteners. These objects are solved by the attachment tool of the present invention.